1. Technical Field
The present invention relates to an optical disk checkup/measuring apparatus for measuring birefringence, skew and the like on an optical disk.
2. Description of the Related Art
Usually, an optical disk manufactured in a factory is checked in such a manner that properties of the optical disc such as birefringence, skew and the like are measured by using an optical disk checkup/measuring apparatus.
Conventionally, such a kind of the checkup/measuring apparatus is composed of one laser diode as a light emitting source and a pair of photodetectors as light receiving/detecting elements, and the one laser diode and the pair of photodetectors are moved by a set width to a radial direction of the optical disk so that measurement is made.
Furthermore, in the case where measurement in a rotating direction of an optical disk is necessary, the optical disk on a turntable is rotated so that measurement is made in the same manner.
With this measuring method, it took a long time to measure the whole surface of the optical disk.
Since the measuring time was greatly longer than a cycle at the time of manufacturing a disk, it was impossible that a checkup/measuring apparatus is incorporated into an optical disk manufacturing apparatus so that the measuring is made on the manufacturing line.
In addition, since a mechanism for accurately cross feeding is required for moving an optical system such as the laser diode and photodetectors to the radial direction of the optical disk, the checkup/measuring apparatus has a complicated mechanism.
In order to solve the above problem, the present invention provides an optical disk checkup/measuring apparatus having a simple structure which is capable of shortening measuring time and of being incorporated into a manufacturing line.
An optical disk checkup/measuring apparatus according to the present invention includes: rotation driving means for driving rotation of an optical disk to be measured; a light emitting portion for emitting a light beam onto the optical disk to be measured; an optically detecting portion for receiving and detecting the light beam reflected from the optical disk to be measured; and an operation processing portion for operating a signal received and detected by the optically detecting portion so as to form a specified signal, wherein the light emitting portion is composed of a plurality of light emitting elements provided in a radial direction of the optical disk to be measured, and the light beams are emitted successively from the respective light emitting elements onto the optical disk to be measured.
According to the above constitution of the present invention, since the light emitting portion is composed of a plurality of light emitting elements provided in the radial direction of the optical disk to be measured, a mechanism for moving the light emitting portion and optically detecting portion to the radial direction is not required, and the measurement is repeated in a state that the optical disk to be measured is driven to be rotated by the rotation driving means so that the whole periphery of the optical disk to be measured can be measured.